0:06Skip to 0 minutes and 6 secondsDementia with Lewy bodies is the second commonest cause of dementia in the elderly. It's a neurodegenerative disease which causes loss of cognitive function and various other fairly specific features as well. Those features are the presence of motor symptoms that look a bit like the symptoms of Parkinson's disease, the presence of cognitive fluctuations. So a patient with Alzheimer's disease, the deficits that they have in their memory and concentration orientation would be pretty constant from day to day. Obviously, they will deteriorate as their dementia progresses. But you can see a patient with Alzheimer's disease on one day and see them a few days or weeks later, and the problems they have are very much the same.

0:45Skip to 0 minutes and 45 secondsNow a patient with DLB, because of the fluctuations they show, their difficulties can be markedly different on different occasions, those fluctuations that make the management and treatment of DLB so difficult and that really make challenges for families. Because they're never quite sure who they're living with and what the level of disability they're dealing with is on a kind of moment to moment basis because of the way it can change.

What is DLB?

Watch Dr Jon Schott and Professor Robert Howard describe the main features of dementia with Lewy bodies.

DLB is the second most common cause of dementia in elderly people

Features include motor symptoms (similar to Parkinsonism) and cognitive fluctuations

What are Lewy bodies?

Lewy bodies are tiny abnormal collections of a protein called alpha-synuclein that develop inside brain cells. The term Lewy body comes from the neurologist Dr Frederic Lewy who discovered the inclusion bodies in 1912.

When you look under the microscope at brain tissue of someone who has dementia there are different changes that might be seen, and this is known as histopathology. In Alzheimer’s disease, the histopathology includes the amyloid plaques and neurofibrillary tau tangles that we learned about in Week 1. In frontotemporal dementia there are a number of different proteins that can build up and cause symptoms (such as tau, ubiquitin and FUS). In dementia with Lewy bodies, the characteristic histopathological feature is the abnormal aggregation of alpha-synuclein in the form of Lewy bodies.